The purpose of this proposed Senior Scientist Award (K05) from the National Institute on Drug Abuse is to provide stability of support for Professor James C. Anthony of the Johns Hopkins University, Bloomberg School of Public Health, in relation to his program of continuing research, research training, mentoring, and science education on the topics of drug dependence epidemiology and enviromics. The research plan and career development activities are organized in relation to five main rubrics of epidemiology and associated research questions: (1) Within the population, how many people are becoming affected by clinically significant syndromes of drug dependence? How many cases have accumulated? (2) Within the population, where are we more (or less) likely to find drug dependence cases, in relation to characteristics of person, place, and time? (3) What accounts for some people becoming drug dependent while others are spared? (4) How do linked sequences of events and processes lead toward the transition from being a non-case to becoming a case of drug dependence, and the hazardous consequences of becoming or being a case? and (5) What can we do to prevent, delay, or reduce the risk of becoming a case of drug dependence, to reduce the duration, or to ameliorate the associated suffering? Whereas the 'genome' refers to the total ensemble of genetic material for a form of life, the 'envirome' is the total ensemble of environmental processes and circumstances required for life form viability and successful adaptation. In complement with genomics and proteomics, drug dependence enviromics is a deliberate search for specific environmental processes and circumstances that promote health by reducing the risk, prevalence, and problems of drug dependence. In drug dependence enviromics, the main objects of study are neither the gene nor the environment, but rather the gene-environment interactions that give rise to drug dependence, prevent or sustain it, interrupt its natural history, and reduce the global burden of drug dependence and associated disabilities.